Use square root and cube root symbols to represent solutions to equations of the form x^2 = p and x^3 = p, where p is a positive rational number. Evaluate square roots of small perfect squares and cube roots of small perfect cubes. Know that √2 is irrational.
x is the square root of a non-negative number n if n^2 = n. For example, 8 is the square root of 64 because 8^2 = 64. It is also true that -8 is the square root of 64 because (-8)^2 or -8 x -8 = 64.
However, the principal square root is the positive form.
x is the cube root of a number n if n^3 = n. Below is the symbol for cube root.
4 x 4 x 4 = 64 so the cube root of 64 is 4.
The cube root can also be a negative number.
-5 x -5 x -5 = -125 so the cube root of -125 = -5.